Sökning: "ecosystem productivity"

Visar resultat 1 - 5 av 76 avhandlingar innehållade orden ecosystem productivity.

  1. 1. Effects of enhanced ultraviolet-B radiation on subarctic ecosystems

    Författare :Carola Gehrke; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pigmentation; photosynthesis; dark respiration; shoot morphology; shoot growth; phanerogams ; species composition cryptogams; productivity; decomposition; dwarf shrubs; bryophytes; peatland ecosystem; heath ecosystem; UV-B; ozone depletion; Plant ecology; Växtekologi;

    Sammanfattning : Biologically harmful ultraviolet-B radiation (UV-B, 280-320 nm) is increasing at the Earth´s surface owing to stratospheric ozone depletion. This is of global concern due to potential impacts of enhanced UV-B radiation on the biosphere. LÄS MER

  3. 2. The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change

    Författare :Maria Myrstener; Ryan A. Sponseller; Reiner Giesler; Ann-Kristin Bergström; Tenna Riis; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nutrients; Stream; Arctic; Boreal; Primary productivity; Algae; Biofilm; Nutrient limitation; Nitrogen; Phosphorus;

    Sammanfattning : Arctic and sub-Arctic freshwaters are currently experiencing substantial ecosystem changes due to the effects of global warming. Global warming effects on these freshwaters include increasing water temperatures, altered hydrological patterns, shifts in riparian vegetation and changes in the export of nutrients and carbon from soils. LÄS MER

  4. 3. Anthropogenic impact on predator guilds and ecosystem processes : Apex predator extinctions, land use and climate change

    Författare :Marianne Pasanen Mortensen; Bodil Elmhagen; Francisco Palomares; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Mesopredators; apex predators; top-down; bottom-up; interspecific killing; red fox; Eurasian lynx; grey wolf; wolverine; productivity; winter severity; cropland; zoologisk ekologi; Animal Ecology;

    Sammanfattning : Humans affect ecosystems by changing species compositions, landscape and climate. This thesis aims to increase our understanding of anthropogenic effects on mesopredator abundance due to changes in apex predator status, landscape and climate. LÄS MER

  5. 4. Connections between biodiversity and ecosystem functioning in large-scale natural ecosystems

    Författare :James Hagan; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biodiversity; ecology; ecosystem function; ecosystem process;

    Sammanfattning : Billions of years of evolution have given us a planet that supports a remarkable diversity of life. Estimates for the number of Eukaryotic species frequently number in the millions and the Prokaryotes are much more diverse than that. This biodiversity makes up the ecosystems that we, as humans, rely on to sustain almost every aspect of our lives. LÄS MER

  7. 5. Nest-site attendance and foraging ecology of the Northern Fulmar (Fulmarus glacialis) on the Faroe Islands. Is the Northern Fulmar a useful indicator of ecosystem productivity and pollution?

    Författare :Johannis Danielsen; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nest-site attendance; foraging ecology; indicator species; Fulmar; Fulmarus glacialis; nocturnal activity; ecosystem productivity; pollution; mesopelagic fish;

    Sammanfattning : The Northern Fulmar (Fulmarus glacialis) is one of the most abundant seabirds in the Northern Hemisphere and the most abundant seabird on the Faroe Islands. Except from a few sporadic observations up until the 1950´s no study has focused on this species on the Faroe Islands. LÄS MER